Residual development over iterations
The discrepancy here is a sort of compounding effect of the pressure drop rhtough the cooling channels being underestimated. When pressure drop rises over cooling channels, higher pressure rise is needed across pump, which again means higher pressure drop across turbine. I decided to leave it in because I do not actually know exactly why the pressure drop in the channels is lower than expected.
Unknown why the reference data has a lower temperature rise than Pyskyfire. If you look at the temperature rise comparison in the regenerative cooling results they are not this excessive.
The discrepancies all over the board is exacerbated by the fact that I am not correcting for ideal vs delivered Isp. This lowers mass flow which has an effect on the whole system. When better Isp estimates are made in the future, these predictions will improve.
I can't figure out why the scaling is bad. I plan on rewriting the engine network visualiser anyways so I will leave this as is for now.
| Parameter | Value |
|---|---|
| p_c | 3275010 |
| MR | 5.05 |
| AR_c | 1.5 |
| F | 73182 |
| p_e | 3770 |
| A_e | 0.708 |
| p_tank_fu | 190800 |
| p_tank_ox | 292000 |
| L_star | 0.95 |
| eps | 56.1 |
| cea_fu | H2 (100%) |
| cea_ox | O2(L) (100%) |
| coolant_fu | Hydrogen (100%) |
| coolprop_fu | hydrogen |
| coolprop_ox | oxygen |
| T_gas_fu_in | 200 |
| T_gas_ox_in | 100 |
| theta_conv | 25 |
| r_c | 0.123 |
| R_1f | 1.5 |
| R_2f | 3 |
| R_3f | 0.5 |
| length_fraction | 0.713 |
| n_fu | 31537 |
| n_ox | 12615 |
| wall_thickness | 0.00031 |
| roughness_height | 1.17e-06 |
| ht_up | 0.0032 |
| ht_lo | 0.00134 |
| pn_up | 0.7 |
| pn_lo | -5 |
| eta_pump_fu | 0.581 |
| eta_pump_ox | 0.642 |
| stage1_fraction | 0.5 |
| eta_turbine_fu | 0.735 |
| eta_stage1_stage2_fu | 0.95 |
| eta_pump_regen_fu | 0.95 |
| eta_regen_turbine_fu | 0.98 |
| eta_turbine_injector_fu | 0.94 |
| eta_fu_injector | 0.88 |
| eta_pump_regen_ox | 0.95 |
| eta_regen_turbine_ox | 0.95 |
| eta_pump_injector_ox | 0.88 |
| eta_ox_injector | 0.88 |
| zeta_stage1_recirc | 0.007 |
| zeta_stage2_recirc | 0.00294 |
| zeta_stage2_gearbox | 0.00294 |
| zeta_turbine_bypass | 0.00427 |
| zeta_pump_ox_recirc | 0.0005 |
| T_tank_ox | 97 |
| T_tank_fu | 22.7 |
| rho_ox_tank | 1.08e+03 |
| rho_fu_tank | 68 |
| thrust_chamber | <pyskyfire.regen.thrust_chamber.ThrustChamber object at 0x00000225A8CA5010> |
| Parameters | Value |
|---|---|
| MR | 5.05 |
| p_c | 3275010 |
| T_c | 3.3e+03 |
| F | 73182 |
| eps | 56.1 |
| L_star | 0.95 |
| c_star | 2.39e+03 |
| p_amb | 100000 |
| Isp_ideal_amb | 451 |
| Isp_vac | 468 |
| Isp_amb | 50.9 |
| Isp_SL | 45.4 |
| CF_vac | 1.92 |
| CF_amb | 0.209 |
| CF_SL | 0.186 |
| mdot | 15.9 |
| mdot_fu | 2.63 |
| mdot_ox | 13.3 |
| t_stay | 0.000975 |
| A_t | 0.0116 |
| A_e | 0.652 |
| r_t | 0.0608 |
| r_e | 0.456 |
| V_c | 0.011 |
| npts | 15 |
This is the report outlining the Pyskyfire simulation of the regenerative cooling of the RL10 engine. Reference data is largely collected from NASA, Binder, 1997, RL10 Modelling Project.